Stapling



'N 7, 1942- DR. LA PLACE STAPLI NG Fi1ed July 5, 1940 INVENTOR Desmond/2 L'aP/ace 'IIIIIIIIIII III IIIIII).VIIIIIIII'IIII'IIII Patented Nov. 17, I942- UNITED STATES PATENT OFFICE Desmond E.

130051 Corporation, tlon of Delaware La Place, Pittsburgh, Pa., assignor to Pittsburgh, Pa., a corpora- App'lication July 3, 1940, Serial No. 343,703

\ 3 Claims.

This invention relates to the art of stapling and is for an improved staple and an improved method of stapling.

At the present time, staples are ver extensively used as fastening meaning in various industries. Such staples are of the conventional inverted U-shaped form. Among staples at the present time is the securing together of the flaps of various kinds of fibre and cardboard containers and cartons. The sealing of cartons presents an especially peculiar problem because of the difiiculty of turning or clinching the points of the staple to make them hold after the staple has been time stapling can be used for' the sealing of cartons only where the carton is so constructed that some kind of an anvil can be inserted under the folds of the carton against which the points of the staple are driven and which turn or clinch the points of the staple. Obviously such a carton cannot be used to contain loose contents of a character which can sift through the opening necessary to permit the insertion and removal of the thin strip constituting the anvil. Another serious limitation to the use of staples at the present time is the fact that the points of the staple have to be driven completely through the overlapping layers of cardboard in which event they are apt to enter, mar or damage the contents of the box.

According to the present invention, there is provided a novel form of staple and method of stapling wherein the points of the staple are automatically clinched or folded in toward each other after the staple has been driven a predetermined distance. This clinching may take place either after the points are completely through the layers which are to be stapled, or they may be clinched after they have entered a predetermined distance but before the points have completely penetrated the full thickness of the material. For example, according to the present invention, there is provided a staple or like driven fastener which can be used for the sealing together of overlapping layers-oi a carton where the legs of the staple will pass completely through the top layer and enter the underlying layers and be bent together within the thickness of such underlying layer so that they do not penetrate the full thickness of the underlying layer and therefore cannot damage or injure the contents of the box or carton. The invention further provides a staple and method the important uses of driven. At the present is effected entirely without the use of any anvil and is controlled entirely from the driver.

In my copending application, Serial No. 346,959 filed July 23, 1940, there is disclosed a driver for driving the staples herein disclosed in accordance with the method herein described. According to the present invention, the leg of the staple itself is provided with an outwardly protruding burr or projection thereon intermediate the length thereof. This burr or projection is preferably formed in a manner such as to weaken the resistance ofthe leg to bending at the point where the burr is formed. The staple is driven in the usual manner and then a follower moving down the outside of each leg of the staple, striking the burr, creates a bending moment tending to bend the points of the staples. The extent to which the legs are bent inwardly is determined by the travel of the follower.

My invention may be more fully understood by reference to the accompanying drawing which illustrates certain embodiments of my invention and in which:

Figure I is a perspective view showing a row of staples constructed in accordance with the present invention positioned above overlying layers of corrugated fibre board with the driving element positioned over the staple which is to be next driven;

Figure II is a side elevation of one of the staples embodying my invention;

Figure III is a transverse vertical section through the staple shown in Figure II;

Figure IV is a more or less schematic view illustrating the first step in the method of driving the staple;

Figure V is asimilar view showing a staple partly driven;

Figure VI is a view ing the ends of the staple clamped or gether;

. Figure VII shows the staple in place with the driver removed. In. Figures IV to VII inclusive, the views are transverse vertical sections through the overlapping layers of material through the staple and through the driver, where the driver is illustrated;

Figure VIII is a view similar to Figure VII showing a modification wherein the ends of the staple are turned without having penetrated the full thickness of the underlying layer of the corrugated fibre board;

Figure IX is a view similar to Figure VIII but similar to Figure V showbent toof stapling in which the clinching of the staple on a larger scale;

Figure X is a modification showing a slightly different form of fastener; and

Figure X1 is a perspective view showing still another modification.

Referring first to Figures II and III, the staple is illustrated as being of conventional form formed of narrow flat strip material having a cross bridge 2 and parallel legs 3. The ends of these legs may be square or they may be sultably sharpened or chiseled to facilitate the entering of the staple into the material into which it is to be driven. Each leg isprovided intermediate its ends with a protruding burr or lug l' thereon. The lug is preferably formed by punching the metal from which the staple is formed in such manner that the lugs 4 comprise outwardly and upwardly extending tongues that are severed along the top sides thereof from the metal, being attached to the metal along their bottom edge along the line marked 5 in Figure II. This punching of the metal not only serves to form the lug 4 but also serves to weaken the leg transversely in the transverse plane of the lug 4 as shown by the bending line A-A in Figure II.

In the operation of stapling, the staples are usually delivered in succession to a driver. In Figure I there is shown such a succession of staples 2. B designates one of two overlying thicknesses of corrugated cardboard or fibre board, and B designates the other layer. B and B may, for example, be two overlying flaps at the end of a carton. In the conventional practice of stapling, the staples are at the present time usually driven diagonally to both edges of the carton, and in Figure I they have been illustrated in a position diagonal to the free edges of the sheets B and B. In Figures IV to IX, however, no attempt has been made to indicate such positioning of the staple, and it will be understood that the position or direction of the staple with reference to the material in which it is to be driven is unimportant and forms no part of the present invention, and is mentioned here only to indicate that the staple may be used in the conventional ways that ordinary staples are now employed.

According to the present invention, the staple as shown in Figures II and III is driven into the material to its full limit and then the points are turned inwardly. In Figures-I and IV to VIII inclusive, the method of stapling is clearly illustrated. The driver which forces the staple into the material and which may be of any suitable construction and may be either manually or mechanically operated is designated C, and D indicates a follower which preferably is associated with the driver but which may be separate therefrom. When the staple has been brought to the proper position on the top layer B of the carton or other surface into which the staple is to be driven, pressure is applied to the top of the staple by means of the driver C. This forces the staple into the material to the full depth permitted by the cross bridge 2. When the staple has been driven to the full depth to which it is or can be moved by the driver C, the legs D of the follower which are spaced a width equal to the outside width of the staple are forced downwardly. These legs D of the follower are preferably of the width of the staple, and while being quite thin, are formed of a rigid material. They may be sharpened very slightly as illustrated to facilitate their entering the material. Preferably, the legs D of the follower move down into the material along the outside of the staple as the staple is being driven as illustrated in Figure V. When the further downward movement of the staple and the driver C is stopped, the legs of the follower continue to move on down. They strike and push down on the burrs or projections 4. Since the staple itself cannot be moved down further, this pressure being applied to a point at one side of the plane of the leg of the staple creates a bending moment causing the free ends of the staple to be turned inwardly. This bending moment is made more effective by the weakening of the staple transversely in the general plane of the line A--A of Figure II, while in Figure VI the follower is shown at the full downward limit of its travel, and the free ends of the staple are bent in horizontally. The extent of bending of the free ends of the legs of the staples is determined by the movement of the follower. It is not necessary to effectively hold the staple that the ends be bent at right angles to their original plane. Even if they are bent in to only a slight angle they will, in most cases, satisfactorily hold the material. On the other hand. the staples can be bent past a turn if the movement of the follower is continued beyond the point shown in Figure VI. This, however, is usually not necessary or desirable.

In Figures IV to VII inclusive, the length of the staple is such that when the staple is driven into its full depth as illustrated in Figure V, the ends protrude well below the undersurface of the bottom layer B of fibre board, and the burrs happen to coincide with the plane of the undersurface of the layer B.

When it is desired to turn the ends of the staple inwardly without them projecting at all or only slightly through the bottom layer of material before they are turned, the method illustrated in Figures VIII and IX may be employed. In this case the staple is made of a length insuflicient to completely pass through the lower layer of material or may be of a length such as to barely' pass through the lower layer of material, and the location of the burr is determined to assure bending of the staple within the thickness of the material. The former condition is illustrated in Figures VIII and IX. In this'case, when the staple is driven to its full depth, the legs D 'of the follower operate to turn the legs inwardly within the thickness of the lower layer of material B. The points of the staple,.in. movingtoward each. other within the fibre board itself, tear their way through the fibre board. This is especially illustrated in Figure IX where the corrugated layer B is illustrated as being torn away at B and the portion of the corrugation so torn away is caught under the inwardly turned legs and pressed against the layer of fibre constituting the top surface of the sheet B.

From the foregoing description it will be seen that the invention in its preferred embodiment contemplates the provision of a staple having a bridge or head portion and having legs. Each leg is in effect divided into a primary upper portion and a secondary lower portion, and the burr or nib is located at the point of juncture ofthese two portions, and the leg is also preferably weakened in some manner so that when pressure is the fastener is in the form shown in Figures VI and Xi, the leg constitutes an inverted T with the primary portion of the leg intersecting the secondary portion intermediate the ends of the latter In other words, the tongue in the finished staple forms a reverse extension of the terminal portion of the leg to increase the holding power of the staple.

Instead of the staple being formed from fiat sheet metal, it may be formed of either square or round wire, and the burr or nib 4 may be formed in some other way to produce the desired result. Figure X illustrates a modification wherein the fastener is illustrated as having a crossbar or head portion 6 and a leg portion I. Intermediate its ends the leg portion is crimped or bent outwardly in such manner as to form a projection to be engaged by the follower D, and the shape of the bend is such that downward pressure on the top of the offset portion causes the lower portion of the leg to swing inwardly. A complete fastener in the form of a letter C is provided on the completion of the driving operation. It will be understood that the structure shown in Figure X may be made out of fiat sheet metal orthat the modification shown in Figure X may be incorporated in a two-leg fastener instead of a single-leg fastener;

In the modification shown in Figure XI, there is illustrated another form of fastener having a single leg with a crossbar or head 8 and a leg portion 9 which is bent at 10 in the manner shown in Figure X, the fastener being of a generally T-shaped form. With this arrangement, however, it is contemplated that the leg will be bent in a plane perpendicular to the body 01" crossbar 3 rather than parallel with it as illustrated in the preceding modifications.

My invention as described, provides a fastener of the staple type having one or more legs with a bending nib or burr intermediate the end of each leg by means of which the free end portion of each leg may be caused to turn at an angle to the original axis of the leg by the application of pressure to the top of the nib or burr. The nib or burr is so designed that it does not obstruct or increase the difliculty of driving the staple.

While I have illustrated and described certainpreferred embodiments of my invention, it will be understood that the invention is not confined to the particular construction and arrangement of the parts illustrated but that various modifications may be made in both the staple and in the ways of using it within the contemplation of my invention and under the scope of the following claims.

I claim as my invention:

1. A fastener staple having a bridge portion and having depending legs, each leg having means causing it, when driven, to take the form of an inverted T in which each crossbar forming one terminal of the staple is connected to its leg of the staple intermediate the ends of the said crossbar.

2. A staple having a bridge portion and substantially parallel legs formed of an easily deformable metal stock, the legs having tongues formed therein intermediate the length thereof and projecting outwardly and upwardly away from the point of the leg whereby a bending line is formed in the leg of the staple at substantially the plane of the base of the tongue, the tongue being sufliciently wide in respect to the total width of the leg to transmit a bending moment to the terminal portion of the leg when pressure is applied thereto.

3. A fastener of the class described formed of bendable material having a leg portion adapted to penetrate the material into which the fastener is to be driven and another portion transverse to the leg designed to limit the depth to which the fastener may be driven, and means projecting from the leg of the fastener intermediate the free end of the leg and said transverse portion which is more rigid than the leg of the fastener in the plane of said means for transmitting a bending moment to the end of the leg below said means when pressure is applied thereto in the direction of the axis of the leg.

DESMOND R. LA PLACE. 

